1. Field of the Invention
The present invention relates to a female screw device and, more particularly, to such a female screw device, which is practical for installation in a motherboard by a SMT (surface mounting technique) automatic machine.
2. Description of the Prior Art
A computer motherboard has a plurality of mounting holes for the mounting of female screw rods to support a circuit board or any of a variety of electronic devices above the motherboard. After insertion of female screw rods into the respective mounting holes, screws are respectively mounted in the female screw rods to fixedly secure the circuit board or electronic device in place. After installation of related parts in the motherboard, the motherboard is delivered to a tin soldering stove to receive a soldering process. According to current motherboard fabrication methods, electronic components are automatically installed in the motherboard by SMT (surface mounting technique). However, because female screw rods have a screw hole extended through the top and bottom sides thereof, they cannot be automatically sucked by the vacuum suction unit of a SMT automatic machine for quick installation in the motherboard. Therefore, workers achieve the installation of female screw rods manually. This manual installation procedure takes much time and labor and, cannot eliminate human errors. In order to eliminate this problem, some manufacturers plug a plastic plug into the screw hole of each female screw rod before its installation so that a SMT automatic machine can suck in the female screw rod for quick installation in a motherboard. However, it is not easy to remove the plastic plug from each female screw rod after mounting in the motherboard. During SMT tin soldering process of the motherboard, the plastic plug may be melted and bonded to the periphery of the screw hole. In this case, it takes much time and labor to clean the screw hole.
In prior art, discloses a female screw device applicable for quick installation in a computer motherboard by a SMT automatic machine. This design of female screw device comprises a female screw rod adapted for mounting in a mounting hole of a motherboard to support an object above the motherboard, and a quick-release cap adapted for fastening to the female screw rod to close the screw hole for enabling the female screw rod to be installed in a mounting hole of a motherboard by a SMT automatic machine. The quick-release cap comprises a cap body and a plurality of springy clamping arms adapted for fastening to the female screw rod to secure the cap body to the female screw rod to block up the screw hole. This design is still not satisfactory in function. Because the springy clamping arms are extended from the periphery of the cap body and adapted for clamping on the periphery of the female screw rod, they may interfere with the installation of other electronic parts in the motherboard.
The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a female screw device, which is practical for installation in a motherboard by a SMT (surface mounting technique) automatic machine without interfering with the installation of other electronic parts in the motherboard. To achieve this and other objects of the present invention, the female screw device comprises a female screw rod adapted for mounting in a mounting hole of a motherboard to support an object above the motherboard, and a quick-release cap adapted for fastening to the female screw rod to close the screw hole for enabling the female screw rod to be installed in a mounting hole of a motherboard by a SMT automatic machine. The quick-release cap comprises a cap body, and a plurality of springy retaining arms downwardly extended from the cap body and adapted for fastening to the screw hole of the female screw rod to secure the cap body to the female screw rod to block up the screw hole.